Backflow retarder



Feb. 6, 1951 w, J. HOENECKE BACKFLOW RETARDER Filed July 21, 1947 Patented Feb. 6, 1951 UNITED STATES PATENT OFFICE '7 Claims.

The present invention relates generally to improvements in the art of transporting fluent materials, and relates more particularly to improvements in the construction and use of devices for resisting and retarding the counter-flow of relatively dense materials being advanced along a conduit against resisting pressure.

A primary object of my invention is to provide means especially adapted for use in connection with the pumping or like transportation of sewage, sludge or other relatively dense fluent materials having large quantities of fibrous constituents through closed conduits.

Another specific object of this invention is to provide improved devices adapted to permit transportation of high density stock in a highly efiicient and extremely economical manner.

Another specific object of my present inven tion is to provide improved devices which are simple in construction and which may be readily installed in a pipe or like conduit for efiectively resisting back flow of fluent materials of relatively high density being advanced therethrough.

A further specific object of the invention is to provide an improved highly eflicient back fiow retarder or barrier for a closed conduit which is adapted to offer minimum resistance to dense materials being advanced through the conduit against resisting pressure while providing maxi mum resistance to flow of the materials in a reverse direction.

Another specific object of the present invention is to provide improved and simple back flow resisting means especially adapted for use in conjunction with a pump for efficiently conveying high density fluent stock through a closed conduit against resisting pressure.

An additional specific object of my present invention is to provide an improved back flow retarder comprising, a series of elements mounted in spaced-apart relationship on the inner wall of the conduit through which material is adapted,

to be advanced against resisting'pressure, the elements having the free surfaces thereof in" clined inwardly in the direction of advancement of the materials.

These and other objects and advantages of the present invention will be apparent from the following detailed description.

A clear conception of the several features con gtituting the present improvement, and of the mode of constructing and of utilizing back flow retarders embodying the invention, may be had by referring to the drawing accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. 1 is a somewhat diagrammatic representation showing a vertical longitudinal section through a typical standard fibrous material transporting pump, the discharge conduit of which is provided with my improved back flow retarder;

Fig. 2 is an enlarged similar fragmentary section througha conduit provided with a slightly modified back flow retarder and showing the active portion of the pump plunger in foremost position;

Fig. 3 is a similarly enlarged transverse section through the conduit and showing an end view of the retarder of Fig, 2;

Fig. i is a likewise enlarged fragmentary longitudinal section through a discharge conduit provided with a further modified back flow retarder and also showing the active portion of the pump plunger in foremost position; and

Fig. 5 is a similarly enlarged transverse section through the conduit and showing an end View oi the retarder of Fig. 4.

While the invention has been shown and described herein "as being embodied in the discharge conduit of a typical pump of the reciprocating plunger or ram type, it is not my desire or intention to thereby unnecessarily limit the scope or utility thereof.

Referring to the drawing, and particularly Fig. 1 thereof, the typical assemblage shown therein as embodying the invention comprises, in general, an upper material supply hopper l5 communicating with a lower discharge conduit i l through an inlet opening [2; a material movpump plunger or ram l3 slidable within the conduit H with the free end or active portion it thereof movable past the opening E2, the opposite end of the plunger !3 being provided with a piston l5 reciprocable within a cylinder l6 having suitable ports ll, I8 adjacent its opposite ends for admission of operating fluid under pressure past a suitable valve ill from a source of the plunger [3.

of which is shown in the hopper l and conduit II in Fig. 1. The vanes 20 are barb-shaped with both the leading edges 22 and the trailing edges 23 thereof inclined inwardly toward the center of the conduit II in the direction of advancement of the materials; and these vanes 20 may be firmly secured to the inner wall of the discharge conduit II in any suitable manner as by welding. As shown, the vanes 28 are preferably arranged helically within the conduit ll so as to twist the advancing material and thereby prevent undesirable resistance to the flow; and in some instances, dependent on the type and density of the stock being handled, it is desirable to provide more than one group of vanes 20.

In actual use of the device, the high density stock, which may' consist of a fluent mixture of liquid and materials having relatively large quantities of fibrous, stringy or lumpy constituents such as meat, rags, leather clippings, paper pulp, or the like, is fed to the hopper from which it moves by gravity through the pump inlet opening I! to the discharge conduit H. As fluid under pressure is supplied to the cylinder It, being directed by the valve l9 alternately through the ports ll, l8, the piston I5 is caused to reciprocate in an obvious manner within the cylinder, carrying the plunger therewith and causing the active portion i l of the plunger l3 to reciprocate in the conduit ll below the opening l2. Obviously, on each forward stroke of the piston l5 and plunger E3, the active portion M of the plunger causes a batch of the material supplied by the hopper [0 through the opening H. to advance along the conduit H toward and past the vanes ZOI Because of the barb-like shape of the vanes 20 and the helical arrangement thereof within the conduit, the relatively dense fluent stock is advanced past the vanes 20 with a minimum of resistance offered thereby; but once beyond the vanes 28 within the conduit II, the inclined surfaces of the trailing edges 23'of the vanes offer maximum resistance to counter flow of the materials particularly because of the fibrous, stringy and/or lumpy make-up of the materials which catch on the surfaces of the edges 23.

As back flow of the materials being advanced against resisting pressure in the conduit l I, is effectively checked or retarded by the vanes 29, the piston and plunger l3 continuously reciprocate with the active portion from the hopper [0 through the conduit II and past the vanes or barbs to the desired 10- cality.

Referring to Figs. 2 and 3, the back flow retarder shown therein is substantially like that hereinabove described with reference to Fig. 1 comprising, an annular series of substantially radial fins or vanes 20' confined within the conduit vll beyond the limit of travel therein of 26' are slightly modified ,in that the inclined leading edges 22' thereof are formed sharp as and 3 are likewise preferably arranged helically to twist the advancing material as hereinabove M of the. plunger advancing additional batches of stock However, the barb-shaped vanes .1'

described, and a, considerable number of these vanes may be utilized in one or more annular groupings as found necessary without causing excessive resistance to flow of the advancing stock. v

Referring to Figs. 4 and 5, the modified back flow retarder shown therein comprises, an annular series of tapered abutments 28 confined within the conduit H beyond the limit of travel therein of the plunger 13. The modified abutments or barriers 20 are each formed with the leading surface 22" thereof rounded and outwardly flared in the direction of flow of the advancing materials to assume a half-conical shape; and the bases of these half-cones form the trailing surfaces 23 of the abutments 2t and are inclined .inwardly toward the central axis of the conduit H in the direction of advancement of the materials. As in the forms of the device hereinabove described, the barrier plates or barbs 26 are also preferably arranged helically to twist the advancing material; and when the barbs of Figs. 4 and 5 are utilized, it is generally preferable to utilize a fewer number in series than when the vanes or barbs of Figs. 1, 2 and 3 .are used both because of the greater resistance to advancing flow of the type of Figs. 4 and 5 and because of the larger trailing surface 23" which offers additional resistance to back flow. The type of retarder shown in Figs. 4 and 5 may be utilized most effectively where it is not desired to cut up the materials being transported and also when materials of certain consistencies are being handled.

From the foregoing detailed description, it will be apparent that my present invention provides an improved device for resisting and retarding the back flow of relatively dense materials being advanced along a conduit against resisting pressure, thereby making it possible to transport such materials or high density stock for considerable distances by means of a pump of standard construction in a simple, efiicient and economical manner. Without the improved "back flow retarder, the high density stock is found to back up with every rearward movement of the plunger 23, thereby causing jamming of the stock at the pump inlet and consequent failure of the pump. The improved back flow retarders are also extremely simple and durable in construction and may be readily installed in any conduit for use with any type of pump. The vane elements or abutments 20, 2G and 26', when properly installed, ofier minimum resistance to the flow of high density stock during advancement thereof through the conduit but the training edges or surfaces of these elements are inclined so as to offer maximum resistance to flow of materials in a reverse direction, thereby affording an effective check for back flow of the stock. The improved devices are especiallyadapted for use in connection with the pumping or like transportation of waste, sewage, pulp and the like of high density and stock containing large quantities of stringy and fibrous constituents. Devices manufactured and utilized in accordance with the invention have proven highly satisfactory in actual commercial use in tanneries and the like, and it has been found that pumps may be utilized for transporting high density stock, which would otherwise necessitate other means of transportation, through use of the improved devices.

It should be understood that it is not desired to limit this invention to the exact details of construction, or to the precise mode of use, herein shown and described, for various modifications within the scope of the appended claims may occur to persons skilled in the art to which this invention pertains.

I claim:

1. For use inconnection with means for advancing materials along a closed conduit against resisting pressure, a back How retarder comprising, an annular series of helically disposed spaced elongated elements each mounted along one longitudinal edge thereof on the inner wall of the conduit, said elements having another longitudinal edge thereof inclined inwardly in the direction of advancement of the materials.

2. For use in connection with means for advancing materials along a closed conduit against resisting pressure, a back flow retarder comprising, a series of spaced elements each having an elongated supporting edge mounted on the inner wall of the conduit, said elements having the leading and trailing edges thereof inclined inwardly at different oblique angles toward the central axis of the conduit in the direction of advancement of the materials.

3. For use in connection with means for advancing materials along a closed conduit against resisting pressure, a back flow retarder comprising, a series of radial fins mounted in spaced apart relationship on the inner wall of the conduit, said fins having the leading and trailing edges thereof inclined inwardly in the direction of advancement of the materials, the leading edges of said fins being sharp.

4. For use in connection with means for advancing materials along a closed conduit against resistin pressure, a back flow retarder comprising an annular series of helically disposed radial fins mounted in spaced apart relationship on the inner wall of the conduit, said fins having the leading and trailing edges thereof inclined inwardly in the direction of advancement of the materials, the leading edges of said fins being sharp.

5. For use in connection with means for advancing materials along a closed conduit against resisting pressure, a back flow retarder comprising, a series of half-conical elements mounted in spaced relationship on the inner wall of the conduit with the bases thereof forming the trailing surfaces.

6. For use in connection with means for advancing materials along a closed conduit against resisting pressure, a back flow retarder comprising, a series of half-conical elements mounted in spaced relationship on the inner wall of the conduit with the bases thereof formin the trailing surfaces and being inclined inwardly in the direction of advancement of the materials.

'7. For use in connection with means for advancing materials along a closed conduit against resisting pressure, a back flow retarder comprising, an annular series of helically disposed halfconical elements mounted in spaced relationship on the inner wall of the conduit with the bases thereof forming the trailing surfaces and being inclined inwardly in the direction of advancement of the materials.

WALTER J. HOENECKE.

Name Date Beekman May 6, 1890 Number 

